Iran. J. Ichthyol. (September 2016), 3(3): 161–180 Received: May 5, 2016 © 2016 Iranian Society of Ichthyology Accepted: July 31, 2016 P-ISSN: 2383-1561; E-ISSN: 2383-0964 doi: 10.7508/iji.2016.02.015 http://www.ijichthyol.org Review of the pikes of Iran (Family Esocidae) Brian W. COAD Canadian Museum of Nature, Ottawa, Ontario, K1P 6P4 Canada. Email: [email protected] Abstract: The systematics, morphology, distribution, biology, economic importance and conservation of the pike (Esox lucius) of Iran are described, the species is illustrated, and a bibliography on this fish in Iran is provided. There is one native species in the Caspian Sea basin, introduced elsewhere in Iran. The family is characterized by a flattened, elongate, duck-billed snout, dorsal and anal fins far back on the body near the tail, no adipose fin, teeth on the tongue and on the basibranchial bones behind the tongue are small, jaws have large teeth, branchiostegal rays 10-20, nasal bones are present, the swim bladder is connected to the gut by a duct, intermuscular bones are forked or Y-shaped, no fin spines, pelvic fins are abdominal, cycloid scales, the infraorbital sensory canal on the head has 8 or more pores, gill rakers are present as sharp denticles in patches, no pyloric caeca, the lateral line is complete, and the forked caudal fin has mostly 17 branched rays. Esox lucius is distinguished from other Iranian freshwater fish species by the broad and flat snout and position of the dorsal and anal fins being far back on the body. Esox lucius is distributed across northern Eurasia and northern North America. Iranian populations are at the southern edge of the range for this species. Keywords: Esox, Biology, Morphology, Distribution. Citation: Coad B.W. 2016. Review on the pikes of Iran (Family Esocidae). Iranian Journal of Ichthyology 3(3): 161-180. Introduction only 7 species in a single genus Esox (Eschmeyer & The freshwater ichthyofauna of Iran comprises a Fong 2016) with one species reported in Iran. Coad diverse set of families and species. These form (1987, 1998) and Coad & Abdoli (1996) place the important elements of the aquatic ecosystem and a species in context with the Iranian ichthyofauna. number of species are of commercial or other The family is characterized by a flattened, significance. The literature on these fishes is widely elongate, duck-billed snout, dorsal and anal fins far scattered, both in time and place. Summaries of the back on the body near the tail, no adipose fin, teeth morphology and biology of these species were given on the tongue and on the basibranchial bones behind in a website (www.briancoad.com) which is updated the tongue are small, jaws have large teeth, here for one family, while the relevant section of that branchiostegal rays 10-20, nasal bones are present, website is now closed down. Other families will also the swim bladder is connected to the gut by a duct, being addressed in a similar fashion. intermuscular bones are forked or Y-shaped, no fin spines, pelvic fins are abdominal, cycloid scales, the Family Esocidae infraorbital sensory canal on the head has 8 or more The pikes, pickerels and muskellunge are found in pores, gill rakers are present as sharp denticles in fresh waters of the Northern Hemisphere. They are patches, no pyloric caeca, the lateral line is complete, moderate to large-sized fishes, up to 1.4m. There are and the forked caudal fin has mostly 17 branched 161 Iran. J. Ichthyol. (September 2016), 3(3): 161-180 Fig.1. Esox lucius, female, 64cm and 3.5kg, from drainage canal near Abkenar, Anzali Wetland, courtesy of S. Nouripanah. rays. Morphology: Coad et al. (1995) summarize Pikes are predators on other fishes aided by the morphology. Dorsal fin principal rays 15-19, about posterior dorsal and anal fins which facilitate rapid 6-10 unbranched and 13-18 branched, principal anal darts forward. They are important sport fishes, much rays 12-16, about 4-8 unbranched and 10-15 sought after by anglers for their fighting ability, but branched, pectoral rays 11-17 and pelvic rays 7-13. are not very good eating because of the intermuscular The number of branched rays may be size-related as bones. in smaller fish more anterior rays in the dorsal and anal fins are not branched. Lateral line scales 105- Genus Esox Linnaeus, 1758 148, pored scales 42-56, but difficult to count The characters of this genus have been outlined accurately. Each scale on mid-flank is a rounded above under the family. rectangle. The anterior margin is indented where 1-2 Esox lucius Linnaeus, 1758 radii terminate. The radii split the scale so that the (Figs. 1-4) segments overlap. Circuli are very fine and the focus Common names: Ordak mahi (= duck fish from the is posterior. Gill rakers are broad and spinulose, snout shape), shok, shuk or shook (in Gilaki), shook embedded in the arch skin with the tips of the chehkhab, chekab. [durnabaligi in Azerbaijan; spinules protruding. There are 9-11 pores on the shchuka in Russian; pike; northern pike]. lower jaws (usually 5 on each jaw). Vertebrae 56-65. Systematics: Esox Lucius was originally described The chromosome number is 2n=50 (Klinkhardt et al. from Europe. Nezami et al. (2007) compared fish 1995; Khoshkholgh et al. 2015). The gut is an from the Anzali and Amirkelayeh wetlands using elongate S-shape. meristic and morphometric characters and found Boluki et al. (2015) examined anatomically and significant differences, attributing these to histologically the intestine and Sadeghinezhad et al. environmental conditions. Tabarrok et al. (2015) also (2015) similarly the tongue, in relation to feeding examined fish from these wetlands using habits. microsatellite markers, finding two distinct Meristic values for Iranian specimens are:- populations and evidence of genetic bottlenecks. dorsal fin branched rays 14(in 7 fish) or 15(9); anal Javadian et al. (2013) found genetic differences fin branched rays 11(1), 12(8) or 13(7); pectoral fin between Mazandaran and Gilan samples but none of branched rays 14(9), 15(5) or 16(1); pelvic fin significance. branched rays 8(1), 9(7), 10(6), 12(1) or 13(1); pores Key characters: The broad and flat snout and the on each lower jaw 5(22). dorsal and anal fins set far back on the body are Sexual dimorphism: There is no obvious sexual distinctive. dimorphism. Attempts have been made to sex pike by 162 Coad-Pikes of Iran Fig.2. Esox lucius, Anzali Wetland, June 2012, courtesy of K. Abbasi. Fig.3. Esox lucius, Anzali Wetland, June 2012, courtesy of K. Abbasi. characters of the urogenital region, but these are fins are dusky to orange. Young have 8-12, wavy, hampered by seasonal variations. Abdurakhmanov white or yellow bars which become the bean-shaped (1962) reports on fish from Azerbaijan where head blotches in adults as they gradually break up. There length is greater in males while predorsal distance is a gold to green stripe along the middle of the back and interorbital width are greater in females. in some fish but others are completely dark green. Colour: The overall colour is dark with light spots, There is a stripe below the eye. The peritoneum is although there is variation over the vast range of this silvery. species in the details. The back and upper flank are Size: Attains 1.75m and about 48.0kg, possibly to dark green, olive-green or brownish, fading to a 2.13m and 65.78kg, despite legends of pike up to whitish belly. The flank has 7-9 rows of greenish, 5.0m (Tsepkin 1986; Machacek (1983-2012), yellow to whitish blotches along it. Scales have a accessed 27 July 2012). golden tip. The head sides have wavy, golden or Distribution: Across northern Eurasia and northern yellow blotches and lines and the eyes are bright North America. Iranian populations are at the yellow to golden. The dorsal, anal and caudal fins are southern edge of the range for this species. Found in green, yellow, orange or pale red, blotched and the Caspian Sea basin, from the Anzali Mordab barred irregularly with black. The pectoral and pelvic (=Wetland) and its drainage canals, tributaries and 163 Iran. J. Ichthyol. (September 2016), 3(3): 161-180 Fig.4. Esox lucius catch, Anzali Wetland, June 2012, courtesy of K. Abbasi. the Sia Keshim Protected Region to Gorgan Bay and However, Abdoli & Naderi (2009) do not report it its tributaries such as the Karasu, with other rivers from the Atrak River. including the Atrak, Babolrud, Chalus, Chamkhaleh, This species has been introduced to the Avan Golshan, Haraz, Harisak, Langarud, Safid, Shahrud, River, 7km from Alamut as early as 1956 (Niamir Shazdeh, Sheikan, Siahdarvishan, Siahrud, Tajan, 2001), and to Valasht Lake near Marzanabad, Evan Talar, Tonekabon, Lake Sama in the Alborz Lake northeast of Qazvin, the upper Karaj and middle Mountains, the Lapu Lake, Boojagh Wetland and the Shur (Abhar stretch) rivers of the Namak Lake basin, Amirkelayeh Lagoon near Lahijan, and in Caspian Ghorigol Lake near Tabriz, the Talkheh River in the Sea coastal waters (Derzhavin 1934; Berg 1936; Lake Orumiyeh basin, Marivan Lake in Kordestan, Armantrout 1980; Petr 1987; Wossughi et al. 1991; and the Haft Barm Lakes west of Shiraz (Anonymous Holčík & Oláh 1992; Molnár & Jalali 1992; 1977; Petr 1987; Niamir 2001). Nejatsanatee 1994; Riazi 1996; Ramin1997; Zoogeography: This widely-distributed species Karimpour 1998; Abbasi et al. 1999, 2007; Kiabi et reaches its southern range limit in Iran. al. 1999; Abdoli 2000; Jolodar & Abdoli 2004; Khara Habitat: Pike are solitary and are found in lakes and et al.